Hydrogels for Regenerative Medicine

Regenerative medicine requires materials that are biodegradable, biocompatible, structurally and chemically stable, and that can mimic the properties of the native extracellular matrix (ECM). Hydrogels are hydrophilic three-dimensional networks that have long received attention in the field of regenerative medicine due to their unique properties. Hydrogels have a potential to be the future of regenerative medicine due to their desirable mechanical and chemical properties, ease of their synthesis, and their multiple applicability as drug delivery vehicles, scaffolds, and constructs for cell culture. In this chapter, we have described hydrogels in terms of their cross-linking and then discussed the most recent developments in the use of hydrogels for peripheral nerve regeneration, tooth regeneration, and 3D bioprinting

Flame Retardant Polymer Nanocomposites and Interfaces

The flame retardant efficiency of polymer nanocomposites is highly dependent on the dispersion of the nano-fillers within the polymer matrix. In order to control the filler dispersion, it is very essential to explore the interfacial compatibility between fillers and matrices, which provides a guide for the flame retardant nanocomposites compounding. In this short review, we mainly focus on the thermoplastic polymers and their interactions with the surfaces of the flame retardant fillers. Other physical properties of those nanocomposites such as mechanical properties, gas permeability, rheological performance and thermal conductivity are also briefly reviewed along with the flame retardancy, since they are all dispersion related

Deformation gradients imprint the direction and speed of en masse fibroblast migration for fast healing

En masse cell migration is more relevant than single cell migration in physiological processes of tissue formation, such as embryogenesis, morphogenesis and wound healing. In these situations, cells are influenced by the proximity of other cells including interactions facilitated by substrate mechanics. Here we found that when fibroblasts migrated en masse over a hydrogel, they established a well-defined deformation field by traction forces and migrated along a trajectory defined by field gradients. The mechanics of the hydrogel determined the magnitude of the gradient. For materials stiff enough to withstand deformation related to cellular traction forces, such patterns did not form. Furthermore, migration patterns functioned poorly on very soft matrices where only a minimal traction gradient could be established. The largest degree of alignment and migration velocity occurred on the gels with the largest gradients. Granulation tissue formation in punch wounds of juvenile pigs was correlated strongly with the modulus of the implanted gel in agreement with in vitro en masse cell migration studies. These findings provide basic insight into the biomechanical influences on fibroblast movement in early wounds and relevant design criteria for development of tissue-engineered constructs that aim to stimulate en masse cell recruitment for rapid wound healing

Melt fracture in polymer thin films at strongly attractive surfaces

Ultra-thin film lubricants with nanoscale control of surface morphology are becoming increasingly important due to the recent push for miniaturization of electromechanical devices. In this letter, we report on an interesting phenomenon dubbed “melt fracture” when a high-viscosity film was allowed to dewet from a film of lower viscosity. We attribute this phenomenon to the shearing at polymer/polymer interface and pinning at the polymer/Si interface. Melt fracture occurs when the shear rate is faster than the natural reptation time of polymer chains. We show that the degree of melt fracture is a function of annealing time and polymer molecular weight. Furthermore, we demonstrate that screening of the substrate interactions, allowing the film to slip can reduce the degree of melt fracture

Women in Chemistry and Physics : A Bio-Bibliographic Sourcebook

Edited by Louise S. Grinstein, Rose K. Rose, and Miriam H. Rafailovich ; foreword by Lilli S. Hornig.Includes chapters by former College at Brockport faculty members Patricia Joan Siegel and Kay Thomas Finley: Ruth Erica Benesch, p. 42-49; Katherine Burr Blodgett, p. 65-71; Helen Abbott Michael, p. 405-409. This valuable resource recounts the contributions of women to science. Biographies of 75 women whose work spans nearly three centuries reflect their struggle to study in a chosen field, gain admission to professional societies, and the lack of funding support. The subjects represent many nations, ranging from Hypatia (ca. 370-ca. 415), the ancient mathematician and astronomer, to Marie Maynard Daly, African American chemist, and Chien-Shiung Wu, Chinese American physicist.The selection criteria used were (a) attainment of advanced degrees despite familial and societal pressures; (b) innovative research results in some aspect of chemistry or physics; (c) influence exerted in teaching and guidance of students at the undergraduate and graduate levels; (d) active participation and leadership in professional societies; (e) extensive scholarly publications; and (f) participation on journal editorial boards. The scope was limited to deceased women or those born before 1933.Each alphabetically arranged entry has three parts--a biography, a review of the subject\u27s research, and an extensive bibliography of works by and about the subject. The subject\u27s background is presented as well as any circumstances or influences that affected her career and her significance to science. Throughout, the relevant chemistry and physics are presented in as nontechnical language as possible. Appendixes include a chronological list by date of birth, a list of places of birth and work and scientific fields for each subject, and listings of abbreviations used in the entries. A detailed index follows. Each entry has a different author. --Booklisthttps://digitalcommons.brockport.edu/bookshelf/1207/thumbnail.jp